Signaling system



H. E. SHREEVEI. SIGNALING SYSTEM.

K AE'PLUQTIUN FILED SEPI, l?. 19ML 1,378,982, Patented May 24, 1921.

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HEBERT E. SnEE'VE, 0F IILLBURN, NEW JERSEY, ASSIGNOB T0 WESTERN' limiti?.V TBIG COMPANY, UVCORPOBATED, OF NEW 'YORK, N. Y., A CORPORATION OIE' NEW YORK.

Specification of Letters Patent.

Patented May 24, 1921.

application and september i7, 191s. serial no. 25mm.

To all whom it may concern Be it known that I, HERBERT E. SHREEVE, a citizen of the United States, residing at Millburn, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Signaling Systems, of which the following is a. full, clear, concise, and exact description.

This invention relates to signaling systems, and more particularly to combined wireand radio signaling systems.

An object of the invention is to provide a signaling system for connecting two separated stations by asymmetric channels.

Another object of the invention is to provide a telephone system for connecting two subscribers stations by combined wire andradio links. i

A further object of the invention is to provide a central station with means for connecting an incoming signaling line to radio transmitting and receiving stations.

A still further object of the invention is to provide means at a central station whereby a two-wire telephone circuit may be simultaneously connected to Vone two-wire transmitting circuit leading to a radio transmitting station, and another two-wire receiving circuit Aleading from a radio receiving station.

An additional object of the invention is to provide ata central station connecting a telephone subscribers station to radio transmitting and receiving stations, meansfor keeping the electrical characteristics-of. the central station and its associated apparatus balanced with respect to the connections to the radio stations.

In the drawing, Figure l illustrates diagrammatically the general scheme of signaling circuits between a telephone subscribers set and a radio transmitting station and radio receiving station; Fig. 2 illustrates a scheme of cord circuits atthe central station. Y

Referring to Fig. 1 of the drawing, the signaling station A is connected by a twowiretivo-way transmission circuit l -t-o a central station B 'at 'which the two-Way transmission circuit is connected to two twowire one-way A transmission circuits, the incoming or listening circuit leading from a radio receiving station C and an outgoing generally by element 7.

or talking circuit leading to a radio transmission station D. Station A is represented diagrammatically in the drawing as a telephone subscribers station, but obviously it may be an .ordinary manual or printing telegraph station, or in fact, any other form of electrlc signaling device or selecting apparatus. Station A is one of a number of similar stations, each of which is connected by two-way transmission circuits 2, 3, respectlvely, to jacks J1, J2, J 3 at the central statlon. The cord circuit included at the central station terminates in a plug l? which serves to connect the subscriber to the operators circuit having a series winding to which the incoming one-way transmlsslon line 5 is inductively connected, and a shunt vWindingconjugately related to the series winding and across which the outgoing one-way transmission line 8 is connected. A balancing network at the central station to simulate the impedance of lines l, 2, 3

and their connected apparatus is indicated Y P1 Pai? P3, J4 and l, 5, P6, J5 are conventional plug and jack arrangements for connecting the incoming lines 5 and the outgoing lines 8 to theV central station circuit.

Radio receiving station C comprises an antenna 9, a detector l0, preferably, of the vacuum tube type, and an amplifier l1, which may also be of the vacuum tube type, having an output circuit connected to line 5 to which it supplies detected or audio frequency currents in the Well-known manner. Radio transmitting station D comprises a. modulator 12 of the vacuum tube type to the input circuit of which a Avacuum tube oscillato1-13 and a transmission circuit 8 are indue-tively connected, the output circuit ot the modulator 12 serving to supply modulated oscillations to the ,input circuit of vacuum tube amplifier 48 which connects modulator Vl2 to transmitting antenna 14.

As will be clear from the description of Fig. Il, signal variations originating at sta'- tion A produce correspond-lng variations in line 8 to which station A is connected by the central station circuit.. Signal currents from line 8 and radio frequency oscillations from oscillator 13 are supplied to modulator I2 by which modulated oscillations of radio frequency are transmitted to amplifier 48.

Amplified modulated oscillations are impressed upon antenna 14 and their energy is radiated in the ordinary manner. Ampliier 48 and modulator 12 are asymmetrically conducting and consequently no signals will be transmitted in over lines 8 when oscillations are set up in antenna 14 by radiant energy from another source. Radiant electrical energy from a dist-ant station it of proper frequency, will set up electrical oscillations in receiving antenna 9 and these high frequency oscillations are supplied to detector 10, which in turn supplies detected or audio frequency signaling currents to the line or channel 5 through amplifier 11. These signaling currents traverse line 5 and connected line 1 and produce signal indications at station A. Detector 10 and ampliier 11 are asymmetrically conducting; line 5 serves therefore as a channel for incoming signals. It should be noted, however, that since the incoming and outgoing channels are conjugately related at station, there is no tendency for energy transmitted from station D to be received at station C and cause singing of the radio circuits even when antennae 9 and 14 are both tuned to the frequency of the oscillations generated by oscillator 13. From one point of view, twovray signaling is carried on over a single wire channel from station A to station Bg over two two-Wire one-way channels from .station B to stations C and D; and by two radio channels to the distant signaling station which, as in the case of transatlantic communication, may be connected to a system similar to that illustrated in Fig. 1. 1t will of course be understood that there may be as many stations C for receiving and as many stations D for transmitting radio messages as desired and that an station C may be used with any station g regardless ot their locations.

Referring to Fig. 2, which shows the cord circuits at the central station, a single signal station A, sh'own by Way of example as an ordinary telephone subscribers station, is connected by line 1, which may contain any number of toll lines and repeating stations, to the. jack J, at the central station B. The circuits at station B consist of three sections 15, 16 and 17 which may be respectively termed the line section. the repeating section and the artiiicial line or balancing section, and are so designed as to automatically balance, Whether the subscribers line and associated apparatus and the operators set are connected or disconnected. Section 15 terminates in the tip and ring contacts of plug P and is inductively related to repeating section 16 by repeating coils 19. Normally, when plug P is disconnected from a jack, sectionV 15 balances section 17. Aconductor 20 containing an artificial impedance simulating the impedance of subscribers station A and its transmission circuit 1 is normally bridged across section 15 and a correspending impedance conductor 21 is bridged across section 17 which is connected to repeating section 16 by coils 22. The character and value of the impedances used in conductors 2O and 2l depend upon the characteristics of the line 1 which is to be balanced. Incoming currents from the radio receiving station traverse line 5, jack J4, plug P3, circuit 23, and are repeated over coils 24 to section 16. Connected in conjugate relationship to the windings of coil is a bridge 25, including auto-transformer 26 across which the outgoing circuit 27 leading to the radio transmitting station is connected. The operators listening circuit 28 is inductively related to sections 15 and 17 by similar transformersi29 and so docs not dlsturb the balance of the two sections and their connected circuits. The operators talking circuit 30 may be connected across section 15 by means of key 31 and the same operation of the key closes circuit 32 bridged across section 17 and containing an artiiicial operators talking circuit designated generally by numeral 33, this artificial circuit serving to balance circuit 30 and its connected apparatus.

Upon removing the receiver from its switchhook, the subscriber at station A closes the usual circuit 'from battery through' one Winding of line relay 34, back contact 35 ot cut-off relay 36. over line 1 and back through front contact 37 of cut-ott relay 36, a second winding of line relay 34 and battery 38,

Line relay 34 is energized, closing a circuit at contact 39 and causing the energization of signal device 40. The operator observing the energized condition of'signal device 40 inserts plu"v P into the corresponding jack J1, completing an energizing circuit for cut-oli relay 36 which may be traced from ground through winding of relay 36 `to sleeve contacts of jack J, and plug P,

relay 42, conductor 43, lower winding of core 41` through the front contact of relay 6 and its armature, to ground. Relay 42 is no7 energized and completes a circuit from ground through its armature and front contact, Winding` of relay 44 and battery 45 to ground. Relay 44, in energizing, pulls up armature 49 opening the circuit through answering supervisory lamp 50y which was momentaril closed by the hack armature of relay 6. elay 44 moves the armature 46 from its back contact to the front` contact thereby opening theI bridge circuit and closing the talking current path through non-inductive resistance 47 in shunt to the winding of relay 42. The-impedance characteristlc of circuit 20 should be as nearly as possible that of circuit 1 and its connected apparatus. The operator in effect cuts circuit 20 oil' the line and substitutes therefor an equivalent impedance without sections 15 and 17 are thus kept balanced at all times. Incoming signal currents are repeated from circuit 23 through coil 24 to section 16, and outgoing signal currents are ceivin-g apparatus.

impressed from line 1 through repeating coils 19 upon section 16 and circuit'27 which is bridged thereacross. Circuits 23 and 27 which connect the high frequency apparatus to the central station, are in effect radio trunks or toll lines' by which one subscriber may communicate with another.

Y Although circuits 23 and 27 have been described in connection with radio signaling receiving and transmitting systems re- Y spectively, it is obvious that any signaling `circuit comprising two one-way circuits constituting electricallyl independent incomingv and outgoing channels may be connected by circuits such as disclosed. herein to an. ordi-- nary two-wire. signaling line; In thecase of radio transmission, the particular radi-oapparatusl disclosed may bel replaced by' any othery suitable radio transmitting and re# The system disclosed may equally well be applied to other forms of electric signaling; and to electric` selecting systems. The' invention is therefore not to he limited to the arrangement disclosed, but only by' thel scope of the appended claims.l Y

T)Vhat is claimed is:

1. In combinatiom means for receiving` radio signal waves and for detecting said waves, a central station, an asymmetric re# ceiving channel connected to said detecting means andfterminating at said central` station independent means forI transmitting radio signal waves modified accordance with signals, an asymmetricy transmitting channel connected: to said independent means and terminating at said' central statiom a. tWo-Way'signal line terminating atl sald cen tral station and means at said central station. for connectingaid signal line to said transmitting channel and said receiving channel at will.

2. In combination, means for receiving and detecting carrier waves, a central station, an asymmetric receiving channel connected to said means and terminating at said station, independent means for transmitting carrier waves modified in accordance with signals, an asymmetric transmit- Y ting channel connected to said independent means and terminating at said central station, a two-way signal liner terminating at said central station, and a cord circuit for conjugately connecting said` channels to said signal line at will.

3. A signaling system comprising a transmitting station, a receiving station, a subscribers station, and a central station Aconnected by independent circuits to each of the aforesaid stations, the circuits leading to'said transmitting and said receiving stations being asymmetrically conducting..

4.. In a signaling system, a plurality of electrically independent asymmetric channels, a. two-wirev circuit, and means for connecting said two-wre circuit to any two of said channels which are oppositely directed.

5. In a signaling system, two. asymmetric signaling' channels, a two-Wire circuit, a central station for connecting said channels to said circuit,v and means at said central station disconnected when said circuit is connected for simulating the impedance of said circuit and its associated apparatus.

6. In a signaling system, two asymmetric signaling channels, a two-wire circuit, -a central station for connecting said channels to said circuit, said station comprising a 105 repeating section in which said two signaling channelsare conjugately connected, a line section connected to saidV repeating sec tion anda balancing section simulating the impedance osaid line section and connected 110 t0y said repeatingsection in such manner as to balance said linesection.

7. In a signaling system, two asymmetric signaling channels, a two-wire circuit and a central station for connecting said channels 115 to said circuit, said station comprising a repeating section in'which said two signalling channels are conjngately connected, a line section connected to said repeating section, and a balancing section simulating the im- 120 pedance of said linesection and connected to said repeating section in such manner as to balancev said line section, said station also comprising means` disconnected when said circuit is connected for simulating they im- 125 pedance of saidv circuit and its. associated apparatus;

8. In ai signaling system, two asymmetric signalingV cliannels,v a two-wire circuit, a central station for connecting said channels 130 to said circuit, means at said central station disconnected when said circuit is connected for simulating the impedance of said circuit and its associated apparatus, an operators set for the central station operator, means for connecting said set to said circuit, and an artificial operators set controlled by said connecting means to automatically maintain the circuit balance at said central station.

9. In a signaling system, two asymmetric signaling channels, a two-wire circuit,.and a central station for connecting said signaling channels to said circuit, said central station comprising means for simulating the impedance of said two-Wire circuit to balance the circuits at said central station with respect to said signaling channels, an operators set for the central station operator, means for connecting said set to said twowire circuit, and an artificial operators set controlled by said connecting means to automatically maintain the circuit balance at said central station.

10. In combination, a lurality of asymmetric incoming channe s, a. plurality of asymmetric outgoing channels, a plurality of subscribers lines, a central station and means whereby an operator at said central station may connect any of said subscribers lines to any of said outgoing channels and any of said incoming channels.

11. A wireless telephone system comprising a transmitting antenna, a receiving antenna, an operators station, a subscribers line terminating at said station, independent asymmetric channels connected to said antennae and terminating at saidstation, and means at said station comprising cord circuits for conjugately connecting said channels to said line at will.

12. A signaling system comprising a plurality of radio transmitting stations, a plurality of radio receiving stations and a plurality of signaling stations, and means for connecting said signaling stations to any one of said transmitting stations and any one kof said receiving stations.

13. In combination, a central station, a subscribers station, a two-way signaling circuit. connecting said subscribers station to said central station, a plurality of one-Way carrier channels terminating at said central station, and a cord circuit at said central station having a two-wire termination and a four-wire termination for connecting said two-way circuit to two of said carrier channels.

14. A telephone system comprising a high frequencyl incoming channel, a high frequency outgoing channel normally physically disconnected therefrom, a plurality of subscribers lines, and operators cord circuits t'or connecting said channels to any one of said lines at will.

15. A telephone system comprising a high frequency incoming channel, a high requency outgoing channel normally physically disconnected therefrom, a plurality of subscribers lines and an operators cord circuit having a conjugate four-wire termination and a two-Wire termination for connecting said channels to any of said lines at will.

16. A. wireless telephone system comprising a transmitting antenna, a receiving antenna, a subscribers st ztion and an operators station for connecting said subscribers station to both of said antennae, said operatorf station comprising means to simulate the impedance or said subscribers station when said subscribers station is disconnected. Y

17. A wireless telephone system comprising a transmitting antenna, a receiving antenna, a transmission line and an operators station for connecting said transmission line to both of said antenn, said operators station comprising a network simulating the character-isti@ impedance of said transmission line. i

18. In combination, two separated stations, twqntral operators stations associated respectively with said separated stations by signal lines, an asymmetric channel -for transmitting electrical waves in one direction between said central stations, a separate asymmetric channel for transmitting electric-waves in the opposite direction between saidcentral stations, and an operators cord circuit at each central station for 'conjugately connecting the two asymmetric channels at said central station to the associated signal line at will.

19. In a signaling system, two separated stations` two asymmetric channels connecting said stations, each of said channels comprising means for producing high frequency carrier currents, means for modulating said currents in accordance with signaling currents, a circuit for transmitting low frequencysignal currents from one of said stations to its associated modulator, means for detecting the modulated high frequency currents, a circuit for transmitting the low frequency detected currents to the other of said stations, a two-way signaling line and an operators cord circuit having means for conjugately connecting the terminals ot the two asymmetric channels at one of said stations to said two-way signaling line.

20. ln a signaling system, two separated stations. two asymmetric channels connecting said stations, each ot said channels comprising means for producing high frequency carrier currents, means for modulating said carrier currents in accordance with signal currents, a transmitting antenna for radiating the energy of said carrier currents and a receiving antenna for receiving said radi- Larnaca frequency signal currents from one of .said stations to its associated modulator, means for detecting high frequency currents., a circuit for transmitting the 10W frequency detected currents to the other of said stations, a two-way signaling line, and an operators cord circuit having means for conjugately connecting the terminals of the two asymmetric channels at one of said sta- 10 tions to said two-way signaling line.

21. In combination, a plurality of widely separated radio transmission stations, a plurality of widely separated radio receiving stations, a plurality of subscribers stations and means whereby a central station operator ma connect any of said subscribers stations simultaneously to any of said radio transmitting stations andany of said radio receiving stations.

22. In combination, a central station,

physically separate hi gh frequency incoming and outgoing channels terminating thereat, a subscrihers station, a line connected to said subscribers station and terminating at said central station, an operators circuit at said central station whereb an operator may converse either over said channels or over said line, andan operators cord circuit for conjugately connecting said channels to said line at will.

In witness whereof l hereunto subscribe iny naine this 31st Vday of December, A. D.,

HERBERT vE. SHREEVE. 

